What cam for a 325HP 360?

I'll say 325 is easily had without the pain of headers, or replacing pistons. Just shave the heads .030, add a cam around .455-.470 lift/218-228 duration @50, and a dual plane intake with a nice working 4bbl, and he'd be mighty close. To be sure, I'd mildly home port/gasket match the heads. Done.

400 would require headers, and most likely a better piston for compression.